a couple of big factors haven't been discussed yet.
Are you planning to stay in hostels/hotels or camp?
How much do you weigh and how much does your gear weigh?
Personally I have done quite well with 50-60 miles a day taking a break every fourth day. However I usually stay in hostels or small hotels and eat at grocery stores. By travelling with my wife we are able to keep are gear weight to 15-25 pounds per bike including tools, tubes and tires.
(Look into some of the self-chekc in efficiency motels, some of them cost the same as hostel but you get a private room/shower, much better bed, etc.)
If you can keep your rider plus gear weight under 200, you are in pretty good shape. If you are going fully load your number is going to be a chunk higher. (230ish maybe,
I think 30 a day loaded sounds quite doable (assuming non-mountain terrain). Just remember to take a break day every 3-4 days, try to plan your route as if you were training. Ride your bike around a little on your off days without having it loaded. Remember to eat well!!! Doing this allows your body to actually get stronger as you tour.
I highly recommend getting real bike clothes to wear. Especially shorts!
Read sheldon brown's site for thorough run down of needs/wants, especially about the saddle.
soft does not equal comfy saddle. consider leather.